my 2003 viper srt -10 has a noisy valve train. Does anyone else have this problem?

 

What do you mean by a noisy valvetrain? Are you hearing lifter noise, rocker slap? Is it possible it's just the fuel injectors? Too, sometimes headers make it seem like valvetrain noise when in fact it's simply the end of he combustion cycle as the valve is opening.

 

I guess it's what you are calling "rocker slap". If this is case, are they adjustable? Solid lift or hydraulic camshaft.

 

I'm pretty sure the Viper is a hydraulic cam and the rockers are not adjustable. Adjustable rockers are available though from MoPar and aftermarket. If the oil pressure is OK, you'll probably be alright, but it may be a good idea to have a mechanic listen to it.

 

There shouldn't be any valvetrain noise in the Vipers' V10, it is hydraulic and it's all rollerized, so it should be nice and quiet. The fuel injectors can sometimes get fairly noisy and using to low an octane gas can cause spark knock which sounds like valvetrain noise, I get this when I run anything less than 110 octane in my Roadrunner.

 

110 octane?!? what compression are you running??

 

How noisy is it? If it's a clanking noise then a rod may have come out of rocker cup.



-Matt-

 

No doubt! That's got to be a bunch of compression. What 12:1 or higher?

 

Yep, 110 octane CAM2 leaded race gas. I even tried running a 50/50 mix of Ultra 94 and the 110 CAM2, it helped out alot but still had the spark knock at the higher RPM's before it shifts gears. Only the straight 110 will keep the spark knock away totally. I have tried changing the timing as well as the carburation with no luck.

I have no idea what the compression ratio is, I bought the engine from the guy that put it in and he had gotten it from someone else. It was supose to be a fresh rebuild with only around 1,500 miles on it stock output 440 Magnum/Super Commando at 375 horsepower, but it was said to be slightly lower compression pistons with a little hotter cam to make up for the difference. The only thing I can think of is that it is either far higher compression than the 9:1 or 9.5:1 it was supose to be or maybe the spark knock is from the slightly smaller 383's fuel line that my Roadrunner has since it was originally a 383 car. But then again that would only be a problem with it under hard acceleration and then it should start to buck from the lack of fuel flow and neither is the case. If I run just the Ultra 94 it will spark knock under light to moderate acceleration like when getting on a freeway, which isn't even maybe 1/8-1/4 throttle. And it will do it just in the higher RPM's before it shifts into the next gear when just taking off from a light or stop sign. If I use a 50/50 mix it will not happen unless I'm on the throttle fairly well, but with straight 110 it won't do it at all even at WOT. If it were a starvation issue from the slightly smaller fuel line then I think it would happen with the 110 when I'm at WOT. For having the full 3" dual exhaust from the headers all the way back it sure does punch the air out fairly strong, nothing like my dad's Hemi does but it does have a decent amount of push coming out.